The present invention relates to disc brakes and more particularly to a mechanical actuating device for spot-type disc brakes having a brake pad clearance adjusting device.
In a known spot-type disc brake adapted to be actuated both hydraulically and mechanically, for example, German Patent DE-AS No. 1,575,996, the brake piston is located freely movable axially on an actuating nut and for actuation is acted upon from the inside by an adjusting spindle cooperating with the adjusting device. In this known spot-type disc brake, it is required for the resetting of the adjusting device prior to a pad replacement to unscrew a screw cap and to take out a wedge. This method does not only involve intricate work, but also bears the risk of losing the unscrewed parts. Besides, the wedge may be jammed by corrosion, so that it cannot be removed without difficulties during brake pad replacement.